Using Wood’s glass to enhance the efficiency of a water solar disinfection (SODIS) apparatus with a Fresnel lens[A review of the 21st century challenges in the food-energy-water security in the Middle East]

Solar disinfection, as a low carbon technology, is a sustainable and cost-effective water treatment method, which makes it more likely to be implemented in developing countries. It has been proven that ultraviolet light radiation is effective against pathogens and microorganisms. The aim of this paper is to evaluate the performance of solar disinfection apparatus that is equipped with Wood’s glass and a Fresnel lens. Wood’s glass is a band-pass filter that allows ultraviolet light to go through and blocks most of the remaining spectrum including infrared. This serves a dual purpose. It lets through the part that inactivates pathogens and microorganisms (ultraviolet) and blocks the part that helps the growth of bacteria (infrared). Experimental setup is designed to investigate the effect of Wood’s glass with and without a Fresnel lens on the solar disinfection process. The investigation is done on a batch-based system and on a novel instantaneous water disinfection system. Results of water disinfection process were recorded for each set of experiments taking into considerations vital parameters, such as solar radiation, solar ultraviolet light intensity and water temperature. The results of these experiments showed effective water disinfection up to 85% pathogens removal by the use of daily available solar radiation.